Factors conditioning the distribution of fresh water pulmonates, Biomphalaria spp., Bulinus spp., and Lymnea spp., in Babati District, Tanzania.

by Lydig, Anna

Abstract (Summary)

The aim of this essay was to investigate if different variables affected the distribution of fresh water pulmonate in Babati District, Tanzania. Can the absence of intermediate host be explained by basic vegetation evaluation, pH, conductivity and temperature? Or can it be explained by other factors as animals and vegetation in the surrounding? The study was carried out in Babati District, in Lake Babati, Kiongozi/Farahani River and the irrigation schemes in Matufa and Gichameda from the 23td of February until 7th of March, 2009. The species found during the survey were Biomphalaria, Bulinus, and Lymnea. Only Biomphalaria pfeifferi were present in the genus Biomphalaria. In Bulinus spp., B. globosus, B. forskalii, and B. africanus were present. Lymnea spp. was represented by L. natalensis. Statistical tests were carried out with logistic models. The results of the statistical analysis revealed different significant results for the different snail species present. L. natalensis showed a significantly positive effect of the water temperature and was distributed in water temperatures ranging from 20.9°C to 24.3°C, which is in the lower range in this study. Biomphalaria pfeifferi and Bulinus spp. were significantly affected to an increase in conductivity. L. natalensis did show a significant effect of the type of bottom in the water body, and found muddy bottoms more suitable. Animal activity (livestock) did show a significant effect on the distribution of L. natalensis which found habitats without animals more suitable. Both B. pfeifferi and L. natalensis were significantly affected by vegetation in the surrounding and found habitats with grass, shrubs and trees more favourable before cultivated areas and forests. The statistical analysis made on the data collected in Babati District showed that temperature, conductivity, bottom in water body and vegetation in the surrounding, in general, significantly affected the fresh water pulmonate. Several variables as pH, water flow, canopy cover, vegetation in the water, however, were not significantly affecting the distribution of the snails. Further investigations of interactive effects of variables, however, are necessary to prevent high infection rates of trematodes infecting the pulmonate present in Babati District, Tanzania.

Bibliographical Information:


School:Södertörns högskola

School Location:Sweden

Source Type:Master's Thesis

Keywords:snail distribution pulmonata chemical factors biological babati tanzania biology biologi


Date of Publication:01/01/2009

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